"hand-drawn" graphics can only be done either on paper or by drawing with a tablet or screen tablet and pen in a 2d drawing/animation app. You will have to learn to draw (obviously).
I take it you mean to create characters in a 3D application that LOOK as if they were drawn?
That is still hard work, and a lot of skills must be learned.
Here is a great tutorial that teaches you how to achieve that "cartoon drawn" look from start to finish in Blender.
That will get you started. Good luck!